In recent years, due to an increase in the demand for electrically driven vehicles such as hybrid electric vehicle (HEV) and electric vehicle (EV), the production volume of secondary batteries serving as a driving source of these electrically driven vehicles has been increasing. As for the structure of secondary batteries, there is a well-known bipolar secondary battery which is structured to arrange collector plates in the positive electrode and the negative electrode of a battery element having serially laminated single cells, as disclosed in, for example, JP1997-232003A.
In the bipolar secondary battery according to JP1997-232003A, a collector having a positive electrode material layer arranged only on one side thereof, a collector having at least a positive electrode material layer arranged on one side thereof and a negative electrode material layer arranged on the other side thereof, and a collector having a negative electrode material layer arranged only on one side are laminated via lithium ion conductive electrolyte layers so that the positive electrode material layers oppose the negative electrode material layers entirely. Then, the bipolar secondary battery is provided with a battery element having means for shielding at least the positive electrode material layers, the negative electrode material layers and the electrolyte layers in the laminated body from the external air.